Prior to dialysis vascular access failure (thrombosis), blood flow decreases from a baseline value to zero over some unknown time period. While the natural history and variation of flow prior to access failure is poorly understood, it is known that customary monthly access flow monitoring is not frequent enough in many clinical settings for adequate prediction and prevention of an impending thrombosis. The effectiveness of access surveillance depends on the frequency and accuracy with which monitoring can be performed. Therefore, the VF Doppler Automated Smart Sensor is being developed for continuous real-time flow monitoring during dialysis. We hypothesize that an active motion compensation/tracking control system utilizing feedback technology can be used to produce a commercially viable point-of-care Doppler based blood-flow monitoring device suitable for VF Doppler smart sensor (compact, low-cost, continuous) monitoring for dialysis and for general flow applications for vascular disease. Our research has determined that introducing active transducer motion compensation with the associated feedback mechanisms will allow for signal optimization improving blood flow measurement accuracy that has not been previously realized. Adding this active transducer drive capability introduces significant advantages for a commercializable device enabling practical clinical viability. Not only will it enhance the accuracy of the diagnostic flow measurement, but it also will allow measurements for broader vascular flow applications outside the dialysis setting. Therefore, this proposal will develop and evaluate a real-time transducer motion compensation system based on a magnetic drive mechanism for the VF (volume flow) Doppler smart sensor with feedback control. This proposal builds upon extensive work and will reduce the risk for successful commercial translation of this NIH sponsored technology. PUBLIC HEALTH RELEVANCE: This proposal will integrate a feedback control system and magnetic actuator into a compact, low-cost Doppler automated smart sensor for longitudinal operator-independent blood flow monitoring. This device will improve care and reduce cost for dialysis patients and patients with peripheral arterial disease.